1. Field of the Invention
The present invention provides a multi-staged hinge assembly for a portable electrical device, In particular, the multi-staged hinge assembly having a simplified structure that allows for the reduction in volume of the portable electrical device.
2. Descriptions of the Related Art
Due to the gradual advancement of industrial technologies and electrical technologies, portable electrical devices are becoming increasingly popular and have also gradually miniaturized in volume for good portability. Meanwhile, to satisfy the various needs of users, portable electrical devices have been designed into different structures to provide users with more diversified operation styles.
For example, to allow users to view information displayed on screens of the portable electrical devices more clearly and also to input relatively complex instructions, portable electrical devices now tend to be designed with both a larger and wider display and a keyboard comprising multiple keys. As these members occupy a large volume, common portable electrical devices currently available are mostly of a clamshell or slide design for convenience in use.
A conventional portable electrical device (not shown) made with a slide design comprises a hinge assembly 1 shown in FIG. 1. The hinge assembly 1 is adapted to connect two body portions (now shown) of the portable electrical device together to exhibit a certain angle relative to each other so that users can conveniently view information on the screen and operate the portable electrical device. The hinge assembly 1 comprises a spindle 11 with a circular cross-section, and a spring 15, a first cam 13 and a corresponding second cam 14 inserted sequentially on the spindle 11. The hinge assembly 1 further comprises a stopper 16 fixedly disposed on the spindle 11 and a shell 12 with a non-circular inner periphery 122. Additionally, the first cam 13 also has a non-circular outer periphery 132 corresponding to the inner periphery 122 of the shell 12, while the second cam 14 substantially has a circular outer periphery 142. With this arrangement, the first cam 13 is restricted to move along the spindle 11 within the shell 12 and is prevented from rotating. One of the body portions of the portable electrical device connects with the shell 12, while the other body portion connects with the second cam 14. When the pre-compressed elastic energy of the spring 15 is released to provide a thrust force against the first cam 13, the first cam 13 will be driven to move along the spindle 11 and, accordingly, the second cam 14 will rotate around the spindle 11. Thereby, the body portion connecting with the second cam 14 rotates with respect to the other body portion to form a tilt angle, thus providing a better viewing angle for users. However, the conventional shell 12, which used for restricting the movement of the cam structures, increases the volume of the hinge assembly 1, and thus the volume of the portable electrical device will be increased accordingly.
In view of this, miniaturization of the hinge assembly through, for example, a non-shell hinge design without losing the original functions will help shrink the volume, reduce the weight, lower the cost and improve the market competitiveness of portable electrical devices.